Seven - The Dreamcast runs at 640x480 as well, and I can tell you now that games like Soul Calibur and Sega Rally 2 (just to name a few) have almost NO jaggies, even on small, then sprites like wire etc.
The fact is, with GT3, is that it uses a bizarre type of Anti Aliasing. Yes, it uses FSAA, but it only anti alias\'s about 2 metres infront of you and your car. You can see (if you look hard enough) where it begins. It is particularly evident when following a wire fence to the left or right of you, in the background, the fence is REALLY jaggie, but as you get closer, you can see the anti aliasing \'kick in\'.
Anyway, I seen WRC today and its got NO jaggies. I cannot wait to see it on my SONY Monitor (68cm) with RGB!